It is often desirable to provide a system that photographs subjects at remote locations and transmits data representative of the photograph to a base location. As concerns over security increase, more locations, such as automatic tellers (ATMs), have incorporated a photographic identification system in order deter thefts and unlawful acts. Such systems make routine surveillance images of subjects as they present themselves at the location to be protected. By storing images of persons as they present themselves at a location, they are less likely to commit a crime since the image has "pre-witnessed" them.
Images accumulated by a surveillance system are stored on video tape or by other means for later processing. In the event that a wrongful act occurs at a remote location in which images are collected, the images can be cross matched to the approximate time of the act and the identity of the subject, based upon reviewed images can be ascertained. Since the images are stored off-site, the subject cannot access it, thus preventing tampering with the storage device.
While the above-described surveillance systems have become increasingly common at permanent fixed locations, the use of such surveillance in mobile applications has been more problematic. It can prove difficult and unreliable to store the images on board a vehicle since they are prone to tampering. Conversely, storing images at a remote location requires a form of two-way communication with the vehicle in order to transfer the images to the remote base station.
In transferring images, at least two problems arise. First, a reliable transmission medium (radio, for example) and band must be utilized which usually entails the dedication of a specific frequency or frequencies for image transfer. Second, the transmission band must be adaptable to transmit reliable image data over a sufficient distance to insure high reliability within a designated operating range.
The problem of establishing a dedicated transmission band can, itself, dissuade the use of image surveillance in many applications where it may prove economically unfeasible to provide dedicated one or two-way telecommunication links. A typical environment in which surveillance of subjects may be particularly desirable is in the taxicab industry. Taxis are often operated at late hours of night in remote parts of a town or city, Taxi drivers tend to work alone and carry large sums of cash on board. All of these factors have made taxicabs and their drivers an ever increasing target of theft and armed robbery. The ability to remotely store images of passengers, before or as they enter the taxi, would invariably serve to deter would-be thieves from carrying out their plans.
However, as noted above, taxicabs, like other mobile based industries, are often operated at a narrow cost margin and the addition of dedicated transmission lines can prove an unacceptable cost. Additionally, any transmission band chosen, must be adapted to provide reliable communication throughout a wide area of operation, around large buildings and over background interference. These problems can limit the number of bands available for use with an image transmission system.
The ability to transmit scanned images would also be desirable for police wishing to identify suspects or victims and medical and fire personnel wishing to identify a subject.
In view of above-described disadvantages, it is one object of this invention to provide a low cost and versatile image transfer system for use in vehicles such as taxicabs.
It is yet another object of this invention to provide an image transmission system that is relatively easy to operate and that utilizes low cost hardware.
It is yet another object of this invention to provide an image transmission system that does not require dedicated transmission lines or bands.